Interactive periodic table of atomic structure: protons, neutrons and electrons for every element, with atomic number, mass number and isotopes. ElementWorks is a free interactive periodic table: hover an element to preview it, click it for its full card, or pick another view from the Show menu.
Every atom has protons and neutrons in the nucleus and electrons around it. The number of protons is the atomic number (Z) and defines the element. In a neutral atom the number of electrons equals the number of protons, and the number of neutrons is the mass number minus the atomic number. Click an element to see its protons, neutrons and electrons.
| No. | Symbol | Element | Protons (atomic number) |
|---|---|---|---|
| 1 | H | Hydrogen | 1 |
| 2 | He | Helium | 2 |
| 3 | Li | Lithium | 3 |
| 4 | Be | Beryllium | 4 |
| 5 | B | Boron | 5 |
| 6 | C | Carbon | 6 |
| 7 | N | Nitrogen | 7 |
| 8 | O | Oxygen | 8 |
| 9 | F | Fluorine | 9 |
| 10 | Ne | Neon | 10 |
| 11 | Na | Sodium | 11 |
| 12 | Mg | Magnesium | 12 |
| 13 | Al | Aluminium | 13 |
| 14 | Si | Silicon | 14 |
| 15 | P | Phosphorus | 15 |
| 16 | S | Sulfur | 16 |
| 17 | Cl | Chlorine | 17 |
| 18 | Ar | Argon | 18 |
| 19 | K | Potassium | 19 |
| 20 | Ca | Calcium | 20 |
| 21 | Sc | Scandium | 21 |
| 22 | Ti | Titanium | 22 |
| 23 | V | Vanadium | 23 |
| 24 | Cr | Chromium | 24 |
| 25 | Mn | Manganese | 25 |
| 26 | Fe | Iron | 26 |
| 27 | Co | Cobalt | 27 |
| 28 | Ni | Nickel | 28 |
| 29 | Cu | Copper | 29 |
| 30 | Zn | Zinc | 30 |
| 31 | Ga | Gallium | 31 |
| 32 | Ge | Germanium | 32 |
| 33 | As | Arsenic | 33 |
| 34 | Se | Selenium | 34 |
| 35 | Br | Bromine | 35 |
| 36 | Kr | Krypton | 36 |
| 37 | Rb | Rubidium | 37 |
| 38 | Sr | Strontium | 38 |
| 39 | Y | Yttrium | 39 |
| 40 | Zr | Zirconium | 40 |
| 41 | Nb | Niobium | 41 |
| 42 | Mo | Molybdenum | 42 |
| 43 | Tc | Technetium | 43 |
| 44 | Ru | Ruthenium | 44 |
| 45 | Rh | Rhodium | 45 |
| 46 | Pd | Palladium | 46 |
| 47 | Ag | Silver | 47 |
| 48 | Cd | Cadmium | 48 |
| 49 | In | Indium | 49 |
| 50 | Sn | Tin | 50 |
| 51 | Sb | Antimony | 51 |
| 52 | Te | Tellurium | 52 |
| 53 | I | Iodine | 53 |
| 54 | Xe | Xenon | 54 |
| 55 | Cs | Cesium | 55 |
| 56 | Ba | Barium | 56 |
| 57 | La | Lanthanum | 57 |
| 58 | Ce | Cerium | 58 |
| 59 | Pr | Praseodymium | 59 |
| 60 | Nd | Neodymium | 60 |
| 61 | Pm | Promethium | 61 |
| 62 | Sm | Samarium | 62 |
| 63 | Eu | Europium | 63 |
| 64 | Gd | Gadolinium | 64 |
| 65 | Tb | Terbium | 65 |
| 66 | Dy | Dysprosium | 66 |
| 67 | Ho | Holmium | 67 |
| 68 | Er | Erbium | 68 |
| 69 | Tm | Thulium | 69 |
| 70 | Yb | Ytterbium | 70 |
| 71 | Lu | Lutetium | 71 |
| 72 | Hf | Hafnium | 72 |
| 73 | Ta | Tantalum | 73 |
| 74 | W | Tungsten | 74 |
| 75 | Re | Rhenium | 75 |
| 76 | Os | Osmium | 76 |
| 77 | Ir | Iridium | 77 |
| 78 | Pt | Platinum | 78 |
| 79 | Au | Gold | 79 |
| 80 | Hg | Mercury | 80 |
| 81 | Tl | Thallium | 81 |
| 82 | Pb | Lead | 82 |
| 83 | Bi | Bismuth | 83 |
| 84 | Po | Polonium | 84 |
| 85 | At | Astatine | 85 |
| 86 | Rn | Radon | 86 |
| 87 | Fr | Francium | 87 |
| 88 | Ra | Radium | 88 |
| 89 | Ac | Actinium | 89 |
| 90 | Th | Thorium | 90 |
| 91 | Pa | Protactinium | 91 |
| 92 | U | Uranium | 92 |
| 93 | Np | Neptunium | 93 |
| 94 | Pu | Plutonium | 94 |
| 95 | Am | Americium | 95 |
| 96 | Cm | Curium | 96 |
| 97 | Bk | Berkelium | 97 |
| 98 | Cf | Californium | 98 |
| 99 | Es | Einsteinium | 99 |
| 100 | Fm | Fermium | 100 |
| 101 | Md | Mendelevium | 101 |
| 102 | No | Nobelium | 102 |
| 103 | Lr | Lawrencium | 103 |
| 104 | Rf | Rutherfordium | 104 |
| 105 | Db | Dubnium | 105 |
| 106 | Sg | Seaborgium | 106 |
| 107 | Bh | Bohrium | 107 |
| 108 | Hs | Hassium | 108 |
| 109 | Mt | Meitnerium | 109 |
| 110 | Ds | Darmstadtium | 110 |
| 111 | Rg | Roentgenium | 111 |
| 112 | Cn | Copernicium | 112 |
| 113 | Nh | Nihonium | 113 |
| 114 | Fl | Flerovium | 114 |
| 115 | Mc | Moscovium | 115 |
| 116 | Lv | Livermorium | 116 |
| 117 | Ts | Tennessine | 117 |
| 118 | Og | Oganesson | 118 |
Subtract the atomic number from the mass number: neutrons = A − Z. Use the mass number of the isotope you are working with.
The same as its number of protons, which is the atomic number.
Atoms of the same element with the same number of protons but different numbers of neutrons, so different mass numbers.
© 2026 Prof. Rami El Oweini. All rights reserved.